Apparatus and Method for Generating and Parsing Mac Pdu in a Mobile Communication System

1. A method for parsing Media Access Control Service Data Units (MAC SDUs) in a Media Access Control Protocol Data Unit (MAC PDU) in a mobile communication system, the method comprising: checking Logical Channel Identifiers (LCIDs) of MAC SDUs multiplexed in a received MAC PDU from a MAC header of the MAC PDU; determining that a last Length Field (LF) related to a last MAC SDU is included in the MAC header and parsing the MAC SDUs from the MAC PDU according to LFs in the MAC header, if a length of the MAC PDU calculated using the MAC header is equal to a known Transport Block (TB) size; and determining that the last LF is not included in the MAC header and parsing the MAC SDUs from the MAC PDU according to LFs in the MAC header and the absent last LF, if the length of the MAC PDU is different from the TB size.

2. The method of claim 1 , wherein the SDU parsing according to the LFs in the MAC header comprises determining that the last LF is included in the MAC header, if a predetermined reserved bit of the MAC header is set to a value indicating the inclusion of the last LF.

3. The method of claim 1 , wherein the SDU parsing according to the LFs in the MAC header comprises: determining that an LF related to a first MAC SDU is included in the MAC header, if an E field related to the first MAC SDU is set to a value indicating the inclusion of the LF related to the first MAC SDU in the MAC header; calculating an accumulated length of the MAC PDU, taking into account the LF related to the first MAC SDU; and determining that the last LF is included in the MAC header, if the accumulated MAC PDU size is equal to the TB size.

4. The method of claim 3 , wherein the SDU parsing according to the LFs in the MAC header and the absent last LF comprises determining that the last LF being an LF related to a second MAC SDU is not included in the MAC header, if an E field related to the second MAC SDU is not set to a value indicating the inclusion of the LF related to the second MAC SDU in the MAC header.

5. The method of claim 1 , wherein the SDU parsing according to the LFs in the MAC header comprises determining that the last LF is included in the MAC header, if data of an LF length adjacent to an E field set to a value indicating a last MAC SDU is set to a predetermined pattern.

6. The method of claim 5 , wherein the SDU parsing according to the LFs in the MAC header and the absent last LF comprises determining that the last LF is not included in the MAC header, if the data of the LF length adjacent to the E field set to the value indicating the last MAC SDU is not set to the predetermined pattern.

7. The method of claim 1 , wherein the SDU parsing according to the LFs in the MAC header comprises, if an E field related to a first MAC SDU is set to a value the inclusion of an LF related to the first MAC SDU and the LF related to the first MAC SDU is set to a predetermined pattern, determining that the first MAC SDU is the last MAC SDU and the LF related to the first MAC SDU is included in the MAC header.

8. The method of claim 7 , wherein the SDU parsing according to the LFs in the MAC header and the absent last LF comprises, if an E field related to a second MAC SDU is not set to a value the inclusion of an LF related to the second MAC SDU being the last LF, determining that the LF related to the second MAC SDU is not included in the MAC header.

9. The method of claim 1 , wherein the SDU parsing according to the LFs in the MAC header comprises, if an indicator is set to a value indicating the size of a padding added due to the absence of the last LF in the MAC header, checking the size of the added padding by the indicator and parsing the MAC SDUs, taking into account the padding size.

10. The method of claim 1 , further comprising: checking an E field in the MAC header; calculating, if the E field is set to a predetermined value indicating the absence of the last Length Field (LF) related to the last MAC SDU and a length indicator for the last LF, the length of the last MAC SDU, taking into account the absent last LF and the length indicator; and parsing the MAC SDUs from the MAC PDU using the LCIDs and the length of the last MAC SDU.

11. The method of claim 10 , wherein the last MAC SDU length calculation comprises, if the E field is set to a predetermined value indicating the inclusion of the last LF and the length indicator for the last MAC SDU and the last LF is set to a predetermined value indicating that the MAC SDU related to the last LF is the last MAC SDU, calculating the length of the last MAC SDU, considering that the MAC SDU related to the last LF is the last MAC SDU.

12. An apparatus for parsing Media Access Control Service Data Units (MAC SDUs) in a Media Access Control Protocol Data Unit (MAC PDU) in a mobile communication system, the apparatus comprising: a header detector for checking Logical Channel Identifiers (LCIDs) of MAC SDUs multiplexed in a received MAC PDU from a MAC header of the MAC PDU and providing sizes of the multiplexed SDUs using Length Field (LF) lengths predetermined for the LCIDs to an SDU detector; and the SDU detector for determining that a last LF related to a last MAC SDU is included in the MAC header and parsing the MAC SDUs from the MAC PDU according to LFs in the MAC header, if a length of the MAC PDU calculated using the LCIDs and the MAC SDU sizes is equal to a known Transport Block (TB) size, and determining that the last LF is not included in the MAC header and parsing the MAC SDUs from the MAC PDU according to LFs in the MAC header and the absent last LF, if the length of the MAC PDU is different from the TB size.

13. The apparatus of claim 12 , wherein when parsing the MAC SDUs according to the LFs in the MAC header, the SDU detector determines that the last LF is included in the MAC header, if a predetermined reserved bit of the MAC header is set to a value indicating the inclusion of the last LF.

14. The apparatus of claim 12 , wherein when parsing the MAC SDUs according to the LFs in the MAC header, the SDU detector determines that an LF related to a first MAC SDU is included in the MAC header, if an E field related to the first MAC SDU is set to a value indicating the inclusion of the LF related to the first MAC SDU in the MAC header, calculates an accumulated length of the MAC PDU, taking into account the LF related to the first MAC SDU, and determines that the last LF is included in the MAC header, if the accumulated MAC PDU size is equal to the TB size.

15. The apparatus of claim 14 , wherein when parsing the MAC SDUs parsing according to the LFs in the MAC header and the absent last LF, the SDU detector determines that the last LF being an LF related to a second MAC SDU is not included in the MAC header, if an E field related to the second MAC SDU is not set to a value indicating the inclusion of the LF related to the second MAC SDU in the MAC header.

16. The apparatus of claim 12 , wherein when parsing the MAC SDUs according to the LFs in the MAC header, the SDU detector determines that the last LF is included in the MAC header, if data of an LF length adjacent to an E field set to a value indicating the last MAC SDU is set to a predetermined pattern.

17. The apparatus of claim 16 , wherein when parsing the MAC SDUs according to the LFs in the MAC header and the absent last LF, the SDU detector determines that the last LF is not included in the MAC header, if the data of the LF length adjacent to the E field set to the value indicating the last MAC SDU is not set to the predetermined pattern.

18. The apparatus of claim 12 , wherein when parsing the MAC SDUs according to the LFs in the MAC header, if an E field related to a first MAC SDU is set to a value the inclusion of an LF related to the first MAC SDU and the LF related to the first MAC SDU is set to a predetermined pattern, the SDU detector determines that the first MAC SDU is the last MAC SDU and the LF related to the first MAC SDU is included in the MAC header.

19. The apparatus of claim 18 , wherein when parsing the MAC SDUs according to the LFs in the MAC header and the absent last LF, if an E field related to a second MAC SDU is not set to a value the inclusion of an LF related to the second MAC SDU being the last LF, the SDU detector determines that the LF related to the second MAC SDU is not included in the MAC header.

20. The apparatus of claim 12 , wherein when parsing the MAC SDUs according to the LFs in the MAC header, if an indicator is set to a value indicating the size of a padding added due to the absence of the last LF in the MAC header, the SDU detector checks the size of the added padding by the indicator and parses the MAC SDUs, taking into account the padding size.

21. The apparatus of claim 12 , the header detector checks an E field in the MAC header; and the SDU detector calculates, if the E field is set to a predetermined value indicating the absence of the last Length Field (LF) related to the last MAC SDU and a length indicator for the last LF, a length of the last MAC SDU, taking into account the absent last LF and the length indicator, and parsing the MAC SDUs from the MAC PDU using the LCIDs and the length of the last MAC SDU.

22. The apparatus of claim 21 , wherein if the E field is set to a predetermined value indicating the inclusion of the last LF and the length indicator for the last MAC SDU and the last LF is set to a predetermined value indicating that the MAC SDU related to the last LF is the last MAC SDU, the SDU detector calculates the length of the last MAC SDU, considering that the MAC SDU related to the last LF is the last MAC SDU.